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Background/Aims: To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride gas (SF6) versus 100% air as a tamponade for graft attachment.
Methods: Retrospective, comparative, interventional case series including 368 pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK between October 2010 and August 2015 using either air (group 1;191 eyes) or 5% SF6 (group 2;177 eyes) as a tamponade. Rebubbling rate, complications, best corrected distance visual acuity (BCVA), manifest refraction and endothelial cell density (ECD) were analyzed before and at 1 week, 1, 3, 6, 12, 24 and 36 months after surgery.
Results: The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P<0.001). Complications included cystoid macular oedema (n=5, group 1; n=10, group 2; P=0.14) and one case of presumed allograft rejection (n=1, group 2). By the end of the follow up period (12±8 months, group 1; 6±4 months, group 2), BCVA (logarithm of the minimum angle of resolution, (logMAR)) had improved from 1.41±0.63 to 0.27±0.69 (group 1, P<0.001) and from 1.8±0.63 to 0.13±0.56 (group 2, P<0.001). The percentage of eyes with BCVA≥0.2 logMAR was 64.4% (123/191, group 1) and 60.5% (107/177, group 2; P=0.43). Endothelial cell loss at 12 months after DMEK was 44±18% (group 1) versus 33±15% (group 2; P=0.07).
Conclusion: The use of tamponade with 5% SF6 yielded a significantly lower incidence of graft detachments requiring surgical re-intervention with no detrimental effect on graft endothelial cells. Thus, the routine use of 5% SF6 for graft tamponade in DMEK is recommended.